When a user wants to install the content from the installer on an external drive, all external devices might be greyed out in the location select window. This is due to a limitation of our installer program, which does only allow you to install the plugin content on the internal drive in some cases, like for example on macOS.
You can relocate the .blob file manually. Open the plugin in your DAW. It will ask for the new location of the blob file and save it from then on.